bohomolets microbiology lecture#1
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By Ms. Kostiuk from Microbiology departmentTRANSCRIPT
Microbiology
Introduction.
Morphology and structure of microorganisms
Protozoa
Amoeba Paramecium
Fungi (mycota)
Aspergillus
Viruses
Adenovirus Bacteriophage
Medical, Pharmaceutical and Biotechnological Applications
A variety of fermented foods produced by microbes
Medical, Pharmaceutical and Biotechnological Applications
Antibiotics, vaccines
Medical, Pharmaceutical and Biotechnological Applications
Human insulin. Made by
recombinant DNA technology
Microbes Cause Food Spoilage and Decomposition
• Penicillium mold growth on orange • Soft rot on peaches caused by the fungus Monilia
Aspergillus mold on shower curtain.
Mold growth in the home, work environment can lead to respiratory infections and allergies
Antony van Leeuwenhoek Leeuwenhoek was a tailor in Delft, Holland. As a draper, he used magnifying glasses to examine fabrics. He made simple microscopes with which he magnified objects too small to be seen with the naked eye.
Leeuwenhoek`s investigations included observations of tiny organisms he called animalcules (little animals), blood, and other human tissues (including his own tooth scrapings), insects, other. Leeuwenhoek transmitted his findings in a series of letters, from 1674 to 1723, to the Royal Society in London, though which his observations were dissemenated.
The first microorganisms were observed at 1676 by Antony van Leeuwenhoek
Antony van Leeuwenhoek is known as the father of bacteriology and protozoology.
A brass replica of a Leeuwenhoek`s microscope
Leeuwenhoek constructed more than 250 small, powerful microscopes that could magnify up to 300 times.
Lens
Specimen holder
Focus screw
Handle
Using of Leeuwenhoek`s microscope
If you can get the lighting just right, it works
Examples of bacteria drawn by Leeuwenhoek
Leeuwenhoek`s letters, which he transmitted to the Royal Society, contained detailed drawings, some of which clearly show microorganisms.
“I discovered living creatures in rain water which had stood but a few days in a new earthen pot. This invited me to view this water with great attention, especially those little animals appearing to me ten thousand times less than those which may be perceived in the water with the naked eye”.
This is probably the first observation of bacteria.
General properties of microorganisms
Microscopic sizeComparative simplicity of organization High rate of reproductionHigh biochemical activityCapacity for rapid adaptability Widely distribution in worldPossibility of pathogenic properties
MICROBIOLOGY
is the science, which studies
representative of microbe world, their interaction with environment, using of microorganisms for human profit.
Branches of microbiology
Science Area of study Microbial morphology Studies the detailed structure of microorganisms
Microbial physiology Microbial function (metabolism) at the cellular and molecular levels
Microbial ecology Interrelationships between microbes and the environ-ment; the role of microorganisms in the nutrient cycles of soil, water, and other natural communities
Veterinary microbiology
The pathogenic microorganisms causing infectious diseases in animals.
Agricultural microbiology
The role of microorganisms in agriculture. It deals with maintenance of soil fertility, the role of microorganisms in causing plant disease
Oceanic microbiology The microflora of the seas, rivers and others
MEDICAL MICROBIOLOGY
is the branch of science, which studies characteristics of pathogenic representative of microbe world, their interaction with human organism, mechanism of infectious disease development, methods its diagnostics, treatment and prophylaxis.
Branches of medical microbiologyScience Area of study Bacteriology The bacteria – the smallest, simplest single-celled procariotic
organisms
Virology Viruses – minute, noncellular particles that are obligate intracellular genetic parasite living only in cells of host
Rickettsiology Rickettsiae – the celled procariotic organisms which are obligate intracellular parasite
Mycology The fungi, a grope of organisms that includes microscopic forms molds and yeasts
Protozoology The protozoa – animal-like and mostly single-celled organisms
Sanitary microbiology
Microflora of ground, water, air, environment object, food stuffs and other objects for the hygienic characteristic and their estimation as probable sources of pathogenic microorganisms transfer.
Immunology Study immune response of human to microorganisms. An understanding of the causative agents of diseases and the body’s defenses against infectious agents has led to preventive and treatment methods that have reduced morbidity and mortality arising from many infectious diseases
Original methods of microbiological investigation
Microscopy Staining Cultivation Obtaining of pure cultureImmunology methodsModelling using animals Virology methodsBiotechnology and gene-ingenering methods
Morphology and structure of microorganisms
The size of microorganisms
Bacterial shapes and arrangements
Micrococci
Single cocci not joint with each other cell
Arrangements of cocci resulting from different planes of cell division
a. Division in one plane produce diplococci and streptococci
b. Division in two planes produces tetrads and packets
c. Division in several planes produces irregular clusters
Diplococci
These are cocci with couple arrangement
Tetracocci
are cocci, duplicating alternately in 2 mutually perpendicular planes with tetrad formation
Streptococci
Spherical bacteria that form chains, they duplicate in 1 plane and in 1 direction without the subsequent branching of affiliated individuals.
Staphylococci
Cocci , which duplicating in various planes with formation clusters resembling bunches of grapes.
Sarcines
cocci, duplicating in 3 mutually perpendicular planes and forming cubic packages from 8, 16, 32, 64 or more cells.
Rod-shaped bacteria
Spiral-shaped bacteria
Spirochetes
Pleomorphic shape
Mycoplasma pneumoniae
Structure of procariotic and eucariotic cells
Bacterial structure
Comparison of prokaryotic and eukaryotic cells
FEATURES OF CELLS PROKARYOTIC EUKARYOTIC
Cytoplasmic membrane Yes Yes
Nucleus containing a nuclear membrane surrounding DNA
No Yes
DNA associated with Polyamines Histone proteins
Chromosome number 1 More then 1
Ribosomes 70S 80S
Cell wall containing of peptidoglican Yes No
Membrane-bound organelles (mitochondria, lysosomes)
No Yes
Endoplasmic reticulum No Yes
Golgi apparatus No Yes
Mitotic division No Yes
Essential structures of bacteria
Cell wall with peptidoglycan
Gives rigid support, protect against osmotic pressure
Cytoplasmic membrane
Site of oxidative and transport enzymes
Cytoplasm Motionless colloid system bounding all structures
Ribosome Protein synthesis
Nucleoid Contain genetic material
Mesosome Participates in cell division and secretion
Periplasm Contain many hydrolytic enzymes
Ribosomes
Bacteria ribosomes are the site of protein synthesis, but they differ from eudaryotic cells ribosomes in size and chemical composition.
Bacteria ribosomes are 70S in size, with 50S and 30S subunits
Function of cytoplasmic membrane (plasma membrane)
Enclosing bacteria cytoplasm from cell wall and internal periplasmatic space
Active transport of molecules into the cell Energy generation by oxidative
phosphorylation Synthesis of precursors of the cell wall Secretion of enzymes and toxins
Function of the bacteria cell wall
Define a shape of a bacteria Protect bacteria from environment factors Contain endotoxin in gram-negative
bacteria Consist porin proteins, which play a role in
regulating the passage of small molecules into the cell.
Its polysaccharides and proteins are antigens that are useful in laboratory identification.
Define a Gram staining.
Gram-positive bacterial cell wall
Gram-negative bacterial cell wall
Gram-stained bacterial mix
Purple Staphylococci are gram positive
Red rods are gram negative
Scanning electron micrograph of Mycoplasma pneumoniae
Cells like these that naturally lack a cell wall exhibit
extreme pleomorphism
Nonessential structures of bacteria
Capsule Protects against phagocytosis
Pilus or fimbria Common pilus - attachment to cell surfaces sex pilus – attachment of two bacteria during conjugation
Flagellum Motility
Spore Provides resistance to unfavourable conditions
Granule Storage sites of food
Plasmid Contains a variety of genes for antibiotic resistance, toxins
Bacterial flagella
Flagella are organelles of movement
Flagella consist protein those are antigens, and this properties may be used for identification of bacteria species.
Arrangements of flagella on surface of bacterial cell
Colorized electron micrograph of Vibrios’s monotrichous (polar) flagellum
Colorized electron micrograph of Salmonella’s peretrichous flagella
Structure of bacterial flagellum
Colorized electron micrograph of E.coli pili
Sex-pili (F-pili) Take part in conjugation process.They join bacteria together prior
to the transfer of DNA from on cell (donor) to the other (recipient)
Common-pili It is a factor of virulence. Its proteins (adhesins) attach
bacteria to cells in the urinary of intestinal tracts of the host as the first step in infection.
Flagellum and pili of E.coli
Bacteria’s spores Spore conditions resistance of the bacterium to heat,
dehydration, freezing, and toxic chemicals This resistance is mediated by thick, keratinlike coat and
dipicolinic acid Vegetative cells develop endospores in unfavourable
conditions Only gram-positive bacteria can form endospore, they called
bacilli The sporogenesis is not bacterial reproduction Spores are located at characteristic positions inside the cell
of different kinds of bacteria, their location can be helpful in identifying the particular species
Clostridium botulinum
These are bacillus that forms subterminal endospores
Clostridium difficile
These bacilli form terminally located endospores
Bacillus anthracis
The endospores are located centrally.
Spore structure
Formation of a bacterial spore
Spores. Acid-fast stain
For visualization of spores may be used special methods of stain, for instance, acid-fast stain
Gram stained bacilli
The capsule or slime layer
mediates adherence of bacteria to human tissue
determines virulence of many bacteria protecting bacterial cells from engulfment by phagocytes
protect cells from perennial effects of desiccation
determines antigen properties of bacterium and can be used for serologic identification
Capsule
For observing of capsule special staining may be used.
Capsules are most easily seen by negative staining, outlined as a light area against a darkened background
Inclusion (granules)
Composition:
glycogen polyphosphate
(volutin granules) protein granules fat drops
Function:
reserve carbon, phosphate and energy source
Volutin granules in cells of Corynebacterium diphtheria
Granules can be seen with special stains
Volutin granules are characterized by metachromasia. Upon staining with special method color of granules is differ from sytoplasm
color